Airfoil construction



Nov. 117, 1931. E. M GUIRE AIRFOIL CONSTRUCTION 2 Shets-Sheet 1 Filed Sept. 16, 1929 INVENTOR.

r'cflfl E. Mia-[31.111 2 M W I ATTORNEYS.

Nov. 17, 1931. E, MCGUIRE 1,832,314

AIRFOIL CONSTRUCTION Filed Sept. 16. 1929 2 Sheets-Sheet 2 a mm 26' INVENTOR.

01d ENC Elmira ATTORNEYS.

Patented Nov. E7, 1933 entree HAROLD E. MCGUIRE, F SHELBY, OHIO AIBFOIL CONSTRUCTION Application filed September 16, 1929. fierial No. 392,996.

The present invention relates to aircraft and more specifically to improvements in the construction of airfoils for such.

V The primary object of the invention is to provide an airfoil of die formed sheet metal construction.

A further object of the invention resides in the provision of a simplified construction for airfoils wherein a greater reduction in manufacturing costs will be had over the present types of airfoil construction.

A further object of the invention is to provide a sheet metal airfoil being relatively light in weight and yet possessing great strength and rigidity for withstanding all manner of strain to which the airfoils are subjected during flight or otherwise.

A further object resides in the novel construction of the main frame of the airfoil whereby all internal bracing such as truss wires, struts and the like are eliminated.

A further and important object of the invention is to provide an airfoil construction comprising in its entirety a minimum number of sheet metal stampings.

A still further object resides in the novel and eflicient manner of hingedly mounting the aileron which is also formed of pressed sheet metal.

Other objects and advantages of the invention will be apparent during the course of the following detailed description, taken in connection with the accompanying drawings forming a part of this specification and in which drawings:

,Figure 1 is a top plan view of the improved airfoil and showing fragmentary portions broken away for illustrating details of construction.

Figure 2 is a longitudinal section on the line 2-2 of .Figure 1.

Figure 3 is an edge view of the airfoil looking at the same from the leading edge.

Figures 4 and 5 are transverse sections on therespective lines in Figure 1.

Figure. 6 is an enlarged fragmentary detail.

section substantially on the line 5-5 of Figure 1 and showing the manner of mounting 99 the aileron.

Figure"? is a transverse section on line 7 7 j of Figure 1.

Referring to the drawings in detail, and wherein similar reference characters designate corresponding parts thruout the several views, the die formed sheet metal airfoil has been shown consisting of eight sheet metal stampings; the letter A designating the main airfoil frame; B the main lower cover plate; C the main upper cover plate; D the aileron frame; E the aileron lower cover plate; F the aileron upper cover plate; G the airfoil hinge member; and H the aileron hinge member.

Referring first to the specific construction 7 and formation of the main airfoil frame A 6 the same is preferably formed from a single die stamping providing front .and rear beam or spar channels 5 and 6 respectively extending at a right angle to the normal direction of motion of the airfoil and a series of evenly spaced apart rib channels 8 extending at a right angle to the channels 5 and 6. The rib channels 8 have their upper and lower surfaces conforming to the general contour of an airfoil with the tapering rear end portions 9 extended rearwardly beyond the rear beam channel 6 and the nose forming forward end 10 of the ribs projecting forwardly of the front beam channel 5 with their forward ends rounded to the shape of the leading edge of the airfoil. A portion of the rear outer end of the frame A is removed rearwardly of the rear beam channel 6 for mounting of the aileron.

The beam or spar channels 5 and 6 are each of inverted trough-like formation including the web portions 11 and downwardly divergmg side plates 12 each having an outtlirned stlifening flange 13 at its lower edge. The outer end of each beam or spar channel 5 and 6 WlllCh projects beyond the outermost rib channel 8 1s tapered to the outer end formation of the airfoil as clearly shown in Figure 12. A false rib 14 shown in Figure 1 is preferably provided between the front and rear channels 5 and 6 for strengthening the outer end edge of the airfoil.

The rib channels 8 which connect and proje'ct beyond the channels 5 and 6 are also of mverted tr ough-like formation having the cambered web 15 and the downwardly diverging side plates 16 each of which is provided along its lower edge with an outturned stifl'ening flange 17 extending contiguous with the flanges 13. The upper surfaces of the webs 15 extend flush with the upper surfaces of the webs 11. The side plates 12 and 16 each have struck out openings 18 for reducing weightrof the frame and each side plate 16 of the rib channels 8 is provided between the openings 18 with outwardly pressed stiffening beads 19. At the diagonal meeting ends of the plates 12 and 16 are outwardly struck corner stiffening beads 20.

The innermost rib forming channel 8 is formed with a straight side plate 16' forming a straight end wall for the inner end of the airfoil. The ends of the base flanges 17 of the rib channels 8 are preferably slightly curled upwardly as shown in Figures 4 and 5 to co-act with the upper surfaces of the webs 15 and form continuous attaching surfaces at the partially open ends of .the channels. Likewise, the flanges 13 at the outer ends of the beam channels 5 and 6 are slightly upturned as shown in Figure 2.

Referring now to the main lower cover plate for the airfoil, the same is formed with a flat body portion 22 conforming to the shape of the main frame A and this body portion 22 is intended to engage upon the base flanges 13 and 17 and be secured thereto in any preferred manner either by welding or riveting. The forward edge of the body portion 22 is curled upwardly over the forward rounded end of the rib channels 8 forming a leading edge moulding 24 extending from end to end of the airfoil. The outer end of the body portion 22 is curled upwardly over the outer rounded ends of the channels 5 and 6 and the false rib 14 forming an end edge moulding 25 alo the outer end edge of the airfoil. The rear e ge of the body 22 is curled upwardly over the rounded rear end portions of the rib channels 8 forming a trailing edge moulding 26 alongthe rear edge of the airfoil from its inner end to the inner end of the aileron. Thus it will be seen that this turning of the front, rear and outer end edges of the cover plate body portion 22 upwardly over corresponding portions of the frame A serve to effectively anchor the marginal pertions of the lower cover plate B to the. main frame A. The inner end of the cover body portion 22 is turned upwardly over the end plate 16 as at 27 in Figure 2. and secured thereto in any preferred manner as by welding, riveting or the like. The moul 24, 25 and 26 may beriveted or spot welded to the frame A.

Referring now to the main upper cover plate C for the main frame A, the same is preferably formed in one piece formed with 'a series of corrugated panel sections 28 spaced apart by narrow plain sections 29.

The corrugations in the panel sections 28 terminate inwardly of the marginal edges of the cover plate and run in the normal direction of motion of the airfoil. These corrugated panel sections 28 provide additional stifiness to the upper cover plate and to the airfoil as'a whole. The front, rear and outer end edges of the top cover plate 0' are joined by a lap joint 30 to the inwardly turned ends of the mouldings 24, 25 and 26 and these joints may be made fast either by spot welding, riveting or the like. The narrow plain plate portions 29 are intended to extend above the web 15 of'the rib channels and may be secured thereto in any preferred manner.

The plain plate portion 29' extending along the rear ends of the outer panel sections 28' extends above and is secured in any preferred manner to the web 11 of the rear beam channel 6 along the point of attachment for the aileron. The inner edge of the cover plate. 1

G is secured to the web of the innermost rib channel8 above the side plate 16'.

Referring now to the aileron frame D the same is in general formation similar to the formation of the main airfoil frame A and flanges 40. The rib channels 34 are formed I with webs 41 and downwardly diverging side plates 42 formed at their lower edges with flanges 43 contiguous with the. flanges 37. The upper and lower surfaces of the aileron frame D conform to the contour of the main frame A as clearly shown in Figures 5 and 6.

The aileron lower cover plate E is adapted for attachment over the lower side of the frame D with the forward edge of the plate extended below the web 35. The rear portion of the plate E is curled the rear end of the rib channels 34 forming a trailing edge moulding 26' along the rear edge of the aileron. The outer end of the plate is similarly curled up over the outer end of the aileron frame forming an end moulding 25'. The cover plate E may be secured to the frame D in any preferred manner as by welding, riveting or the like.

The aileron upper cover plate F for positioning over the upper side of the frame D is formed with the corrugated panel sections 42 terminating inwardly of the front and rear ends of the plate and separated by plain plate portions 43 for extending above the rib channels 34.

The forward edge of the plate F extends upwardly over above the web 35 while the rear and outer end edges of the plate are connected means of a lap joint 44 to the upwardly..and

inwardly turned mouldings 25' and 26. The corrugations of the panel portions 4:2 extend parallel with the corrugations of the panel sections 28.

Referring now to the means for hingedly mounting the aileron'for vertical swinging movement at the rear outer end portion of the airfoil proper, the aileron is mounted with a piano hinge coupling thruout its entire forward edge to a like length of the airfoil proper.

The airfoil hinge member G is formed with upper and lower attaching plates 50 and 51 respectively connected by means of diagonal plates 52 With a series of evenlyspaced apart sleeves 53. As will be observed in Figure 6, the diagonal plates 52 space the sleeve 53 slightly rearward of the main airfoil frame substantially midway between the cover plates B and C.

The aileron hinge member H for attachment along the forward edge of the aileron is also stamped from sheet metal providing upper and lower attaching plates 60 and 61 respectively and diagonal plates 62. Formed along the adjacent edges of the plates 62 is a series of equi-distantly spaced apart sleeves 63 which are adapted to be interposed between the sleeves 53 in axial alignment therewith for forming a hinge barrel for receiving a hinge pin 66. As shown by dotted lines in Figure 6 the diagonal plates 52 and 62 of the hinge members G and H respectively permit free vertical swinging movement of the aileron about the hinge pin 66.

The airfoil hinge member G is adapted to be secured to the airfoil proper by disposing the attaching plate 51 beneath the web 11 of the rear spar channel 6 and the lower attaching plate 51 inwardly of the rear portion of the main lower cover plate B and securing the same by welding, riveting or the like. The upper attaching plate 60 of the aileron hinge member 8 is disposed between the web 35 and cover plate F while the lower attaching plate 51 is disposed above the aileron lower cover plate as shown in Figure 6. The plates 60 and 61 are attached in position as by welding, riveting or the like.

The front spar channel 5 may receive a spar which extends thruout the length of the channel with its upper edge engaging the web 11 and its lower edge engaging the main lower cover plate B. The rear channel 6 receives a spar 71 thruout its length with the upper edge of the spar engaging beneath the web 11 of the spar of the channel and the lower edge of the spar engaging upon the main lower cover plate B. The aileron may also be reinforced by front and rear spars 72 and 73 respectively which are positioned in the channels 32 and 33 respectively. These spars 70, 71, 72 and 73 may either be formed of metal or of wood. By observing Figure 6 it will be seen that the spars 71 and 72 also act to reinforce the hinged connection of the aileron to the airfoil proper.

The portions A to H inclusive are preferably stamped from duralumin but if so desired may be stamped from any suitable material I shaped and constructed as to reinforce one 7 another in such manner as to provide an airfoil capable of withstanding all manner of strain. It will also be apparent that a construction has been disclosed which will materially simplify and materially reduce the cost of construction of airfoils.

Changes in the shape, size and arrangement of parts may be made to the form of invention herein shown and described, with out departing from the spirit of the invention or the scope of the following claims.

I claim:

1. An airfoil comprising a die formed main frame of open construction embodying connected spar and rib channels, a rigid covering secured over the lower side of the frame in contact with the lower sides of the channels,-and a rigid upper covering secured over the upper side of the frame in contact with the upper edges of the channels, one of said coverings forming a moulding at the front, rear and outer end edges of the airfoil.

2. An airfoil comprising a main frame of open construction, a rigid upper cover plate secured over the upper side of the frame with its front, rear and outer end edges spaced inwardly from corresponding edges of the frame, and a rigidlower cover plate secured over the lower side of the frame and having its front, rear and outer end edges curled over corresponding'edges of the frame for attachment to the upper cover plate.

3. An airfoil comprising a main frame of open construction, a die formed lower cover plate secured over the lower side of the frame and having a moulding formed along its front, rear and outer end edges extended upwardly over like edges of the frame, and a die formed upper cover plate secured over the upper side of the frame with its edges secured with a lap joint to the moulding of the lower cover plate.

4. An airfoil comprising in combination a main die pressed frame of open construction embodying integrally connected spar channels and rib channels, a rigid plain surface lower cover plate secured over the lower side of the frame and curled upwardly over the leading, trailing, and outer end edges of the frame, and a rigid upper cover plate secured over the upper side of the frame and connected with the upturned edges of the lower cover plate, said upper cover plate embodying corrugated panel sections spaced by plain plate sections for contact with the upper surfaces-of said rib channels.

5. An airfoil comprising in combination a die formed sheet metal frame of open construction, a plain surfaced die formed lower cover plate secured over the lower side of the frame, said cover plate having its front, rear and outer edges turned upwardly over the leading, trailing and outer end edges respectively of the frame and forming a moulding thereabout, and a die formed upper cover plate secured over the upper side of the frame, said upper cover plate having panels corrugated to extend in the normal direction of motion of the airfoil and with the corrugations terminating short of the front, rear and outer end edges of the upper cover plate forming'plain surfaced bordering edges for connection with a lap joint to the moulding forming portions of the lower cover plate.

6. An airfoil comprising a die formed sheet metal main frame of open construction embodying integrally joined spar and rib channels having their web portions uppermost and outturned flanges along their lower edges, a die formed metal lower cover plate secured over the lower side of the frame to said flanges and having upturned front, rear and outer end edges curled upwardly over like edges of the frame, and a die formed metal upper cover plate secured over the upper side of the frame to said web with the edges of the upper cover plate connected with a sealed joint to the upturned, front, rear and outer end edges of the lower cover plate.

7. In an airfoil, a one-piece pressed metal frame including front and rear spar channels each including a web and downwardly diverging side plates, and spaced apart rib channels connecting the spar channels at spaced points thruout their length each including a web portion disposed flush with the web portions of the spar channels and downwardly diverging side plates contiguous with the side plates of the spar channels.

J 8. In an airfoil, a one-piece pressed metal frame comprising front and rear spar channels and spaced apart rib channels connecting the spar channels at spaced points thruout their length, said spar and rib channels each embodying web portions at their upper face and downwardly diverging side plates joined at the meeting corners of the plates,

said plates being provided with pressed out stiflfening beads and having openings formed therein between the beads. a

9. In an airfoil, a one-piece pressed metal frame including front and rear spar channels each including an upper web portion and downwardly diverging side plates, and

spaced apart rib channels connecting the spar channels at spaced points each including an upper web portion and downwardly diverging side plates contiguous with the side plates of the spar channels, and corner stiffening beads pressed from the metal at the diagonally meeting corners of the side plates.

10. In an airfoil, a one-piece pressed metal frame including front and rear spar channels each including upper web portions, downwardly diverging side plates and outturned stiffening flanges at the lower edges of the side plates, and spaced apart rib channels connecting the spar channels each including an upper web portion, downwardly diverging side plates, and outturned stiffening flanges at the lower edges of the side plates contiguous with the stiffening flanges of the spar channels.

11. An airfoil comprising in combination a die formed main frame comprising spar channels and rib channels connecting the spar channels, a rigid lower covering secured over the lower side of the frame, a rigid upper covering secured over the upper side of the frame With its edges joined to like edges of the lower covering, and a spar arranged longitudinally in each spar channel.

12. An airfoil comprising in combination a die formed main frame of open construction, a die formed lower covering secured over the lower side of the frame, a die formed upper covering secured over the upper side of the frame, a die formed aileron frame, a die formed lower covering secured over the lower side of the aileron frame, a die formed upper covering secured over the upper side of the aileron frame, and die formed hinge members hingedly connecting the forward edge of the aileron members to a rear portion of the airfoil proper.

13. An airfoil comprising in combination an airfoil proper constructed of sheet metal stampings, an aileron constructed of sheet metal stampings, a die formed hinge member carried by the rear edge portion of the airfoil proper, a die formed hinge member carried by the forward edge of the aileron, and a hinge pin connecting the hinge members.

14; In an airfoil construction an airfoil proper, a hinge member secured along a rear portion of the airfoil proper, and an aileron comprising a die formed sheet metal frame including beam and rib channels, a die formed lower cover plate secured over the lower side of the frame and 'havingupturned rear and outer endedges, a die formed upper cover plate secured over the upper side of the frame having its rear and outer end edges secured to the upturned edges of the lower cover plate, a hinge member secured along the forward edge of the aileron, and ahinge pin connecting said hinge members for pi votal mounting of the aileron upon the airfoil proper.

15. In an airfoil construction including an airfoil proper and an aileron, means for pivotally mounting the aileron upon the airfoil proper comprising a pressed metal hinge member including upper and lower spaced attaching plates for attachment along a rear edge portion of the airfoil proper and axially arranged spaced apart sleeves connected by diagonal plates to the attaching plates, a second pressed sheet metal hinge member including spaced apart attaching plates for attachment to the meeting edge of the aileron and axially spaced apart sleeves connected by diagonal plates to the attaching plates, and an elongated hinge pin extending to the aligning sleeves of the hinge members.

16. A hinge mounting for ailerons of airfoils comprising'a pair of pressed metal hinge members embodying upper and lower attaching plates, a diagonal plate extending from one edge of each attaching plate and tubular sleeves formed at the adjacent edges of the diagonal plates in spaced relation therealong, said sleeves of the companion hinge member to interfit one with another to form an elongated hinge barrel, and an elongated hinge pin arranged in said barrel for pivotally o1ning the hinge members.

HAROLD E. MCGUIRE. 

